|
A
Paler Shade of Black
By
Linda Beckerman, Ph. D.
The
jig is up. Thanks to the genetics revolution we now know that
there is no such thing as race. The Human Genome Project (HGP)
has determined unequivocally that there is the same amount of
genetic variation among individuals within a so called racial
group as there is between individuals in different racial
groups. What that means is that there is no real genetic
difference between blacks and whites or between whites and
Asians or between any of the so called races.
Wonder why it's been so hush-hush? I mean, you would think this
would be big news. Certainly on the order of Galileo stating
that the Earth goes around the Sun and not vice versa. But you
haven't heard it on NBC or read it in your local newspaper.
It's more or less kept within the high brow community as if the
common every day man in the street just couldn't take it. So you
can read about it in the Atlantic Monthly or New York
Times, but
not your home town newspaper. And some professors on ivory tower
college campuses are scrambling to prove it isn't so, just like
there some who argue that Darwin was a fruitcake and evolution a
stunt he pulled to grab the limelight.
But if we are all one race, which race are we? One answer is the
cute one that we are the "human race". But buckle your
seat belts folks, because the genetic answer is that we are all
really black. And white people are pale adaptations of black
people that evolved during the past 140,000 years.
From whence does this white skin come? Weren't we all taught
that it was the black people who evolved black skin and it
happened so they would be protected from getting skin cancer?
Forget it. Scientists have thrown the whole notion out. Here's
how evolution works. If you don't live long enough to reproduce,
your genes are lost to the gene pool forever. There being no
high school back when Humans came into being, females started
reproducing around the age of 13. Skin cancer develops later in
life when the female has already reproduced and her genes have
entered the world gene pool. Bye, bye skin cancer theory.
What scientists now believe is that everyone started out with
dark skin in the first place because it is protective against
absorbing too much Vitamin D, which is toxic. Too much vitamin D
causes calcium to be pulled from the intestines and bones and
deposited in soft tissues all over the body, damaging the
kidneys, heart and blood vessels. Dark skin screens out UV
radiation and your body, which uses UV to produce Vitamin D,
produces less of it - a real evolutionary advantage at the lower
latitudes where we began.
So where did the 10,000+ shades of paler brown, beige, pink,
white and what Crayola crayons used to call "flesh"
come from? Archaeological data places the origin of genetically
modern humans in sub-Saharan Africa approximately 140,000 years
ago. Humans then began migrating out of Africa in successive
waves, starting approximately 100,000 years or 5000 generations
ago. Now that scientists have mapped the human genome, they are
homing in on when each wave began their outward bound journey
and where they migrated to. So far they have confirmed that
everyone on the entire planet, even the 1.3 billion Chinese,
have a common ancestor back in Africa.
For example, the first wave appears to have been a migration to
the Middle East and then eastward and northward from there. Some
geneticists studying the human genome map believe that in a
later north moving wave, which occurred about 60,000 years ago,
a mere 50 people inbred together across successive generations
to create all the people who now occupy Europe (excluding recent
immigrants, of course).
But wait a minute, I have blond hair, blue eyes and my hair
isn't nappy and I don't have thick lips. So how can my great,
great, etc. grandfather be a black African? It's all from lines
of genetic inheritance splitting apart and then coming together
again.
Lines of genetic inheritance, or lineages, split apart when
there is a mutation that is evolutionarily advantageous, meaning
the mutation makes it more likely for someone to reproduce
greater numbers of offspring that survive. Someone with a
non-advantageous mutation has offspring that are less likely to
survive.
So as humans migrated out of Africa, why did dark-skinned people
start losing the genetics Powerball Lottery to their paler kin?
Lower UV levels in the sunlight of the more northern latitudes
meant a dark-skinned individual's body could not produce enough
Vitamin D. Insufficient Vitamin D would then result in a child
developing rickets. A child with rickets would not likely
reproduce either because it would die before it could or because
its pelvis would be so deformed it could not pass a child
through the birth canal. Its genes would be lost forever. So
lighter skin, and more absorption of Vitamin D at higher
latitudes would be an adaptive genetic advantage.
Interestingly, in high latitudes where some people still retain
dark skin, such as with the Inuit in the Arctic, the people
obtain significant amounts of Vitamin D from eating fish and sea
mammal blubber.
Seal blubber aside, what about all the other features that make
us look so different? Mutations that endure are often
advantageous to specific climates. For example, the tall thin
body of the Masai warrior dissipates heat while the short squat
body of the Inuit retains it. Long northern European noses
moisten and warm the air before it reaches lungs, while in
Africa short noses remain because the air is already moist and
warm. The Asian's eyelid folds protect their eyes against dry
sandy desert winds and wind driven snow. In the far north, light
sensitive blue eyes allow people to see better when it is dark
much of the year. The tightly coiled hair of the African keeps
the hair off his neck so he remains cooler. All these diverse
physical features promote the promulgation of different lines of
inheritance, or ethnic lineages.
Countering this splitting apart of ethnic lineages is the
melding through interbreeding between different ethnic lineages.
If you walk the Silk Road from Persia to China, across the
southern flank of Asia, you will see a continuum of physical
feature change. You will not be able to tell where the European
look ends and the Asian begins. Remember all those shots during
our assault on the Taliban in Afghanistan and the TV scans of
Afghani children? How many looked European and how many looked
Asian?
Many mechanisms for melding ethnic lineages have been at play.
The rape part of the plunder and pillage drill by invaders,
traders passing through with silver to buy bedtime favors,
marriages for political convenience to form alliances between
not so friendly tribes, and the boy and girl from neighboring
tribes sneaking out for a little tryst under the stars, have all
contributed to the recombining of diverse ethnic lineages.
So what we have instead of the meaningless terms Caucasian,
Negro, Asian, etc., is a large multiplicity of ethnic lineages,
all of whom descended from only a single black race. So don't
forget, next time you fill in the U.S. Census you should write
in the word Black next to the question about your race,
regardless of your shade of pale.
Copyright
by Linda Beckerman, Ph.D. November 2002
beckerman@cfl.rr.com |